Green hospitals: Mitigating water footprint and greenhouse gas emissions through sustainable menu planning in Turkish state university hospitals

Abstract Considering the importance of sustainable nutrition, it is important that hospitals' meal menus are planned to ensure the lowest possible environmental footprint. In this study, we aimed to evaluate the environmental effects of hospital menus and the changes that may occur when these menus are planned according to the Turkey Dietary Guidelines and Mediterranean diet recommendations. In this context, first, the yearly environmental footprints of the standard meal menus of the state university hospitals in Turkey (n = 42), including water footprint (WF) and greenhouse gas emission (GHGE) values, were determined. Second, changes in the environmental footprint as a result of arranging the standard meal menus of state university hospitals according to the Turkey Dietary Guidelines and Mediterranean nutritional models were evaluated. It was determined that the average WF and GHGE values of hospital menus were 137,280 ± 18537.2 L/month and 140.0 ± 18.4 kg CO2‐eq/month, respectively. Adjusting state university hospitals' standard meal menus according to Turkey Dietary Guidelines and Mediterranean nutritional models reduced WF by 24.8% to 103206.7 L/month and 37.8% to 85420.5 L/month, and GHGEs by 31.7% to 95.5 kg CO2‐eq/month and 49% to 71.3 kg CO2‐eq/month, respectively. In addition, it was determined that hospital meal menus planned according to the Turkey Dietary Guidelines and the Mediterranean nutritional model contained lower saturated fat and cholesterol and higher dietary fiber. In conclusion, planning hospital menus according to the Turkey Dietary Guidelines and Mediterranean nutritional recommendations can reduce the environmental footprint of hospital food services.


| INTRODUC TI ON
Among numerous global environmental challenges, climate change is recognized as the greatest global health threat of the 21st century, carrying serious implications for human health through extreme weather events, changes in infectious disease patterns, increased food insecurity, and degradation of air and drinking water quality (Costello et al., 2009;Watts et al., 2015Watts et al., , 2018)).
Changes in people's food consumption patterns featuring consumption of highly processed and animal-based foods and moving away from healthier and more traditional plant-based eating patterns cause the current food system to increase both the burden of non-communicable chronic diseases and the severity of the climate crisis (Barbour et al., 2022;IPCC, 2021;Willett et al., 2019).
Considering that food systems disrupt natural ecosystems by generating large amounts of greenhouse gas emissions (GHGE), depleting water resources, and causing land degradation and loss of biodiversity, the importance of transitioning to a healthy and more climate-friendly food system is indisputable (IPCC, 2021; The Lancet Planetary Health, 2019; Willett et al., 2019).
Sustainable dietary models are defined as nutritionally adequate, economically appropriate, culturally acceptable, and environmentally-friendly models (Vieux et al., 2018).Achieving ecologically sustainable food requires coordinated, multi-sectoral changes at local, national, and global levels aimed at improving food consumption patterns (United Nations, 2015;Watts et al., 2018).
Hospital services also include catering services to provide food to patients, staff, and visitors.More than 10 million patients received inpatient treatment in hospitals in Turkey in 2020.Approximately 1.5 million of these patients received care in state university hospitals.Additionally, it was reported that nearly 180 thousand healthcare staff have been working under different titles in state university hospitals in 2020 (The Ministry of Health of Turkey, 2021).
Thousands of meals are served to patients, staff, and visitors in hospitals that operate 24 h a day and 365 days a year, requiring massive amounts of resources, including water, energy, and land, to produce the foods served in these meals.An environmental footprint is created at every step of this food procurement process (Carino et al., 2020;Melikoglu, 2020).
Therefore, professionals aiming to improve the environmental impact of healthcare services need to focus more on the sustainability of the food procurement process (Vidal et al., 2015).However, there are a limited number of studies on the food groups that will render hospital meal menus environmentally sustainable (Carino et al., 2020;Vidal et al., 2015).In light of this information, this study was carried out to: (i) determine the yearly environmental footprint of the standard meal menus of the state university hospitals in Turkey and (ii) evaluate the changes in the environmental footprint (WF and GHGE) as a result of adjusting the state university hospitals' meal menus according to the Turkey Dietary Guidelines and Mediterranean nutritional models.The following equation was used to calculate the number of samples:

| Research design
where n: number of samples to be included in the study, N: total number of samples, P i : ratio of the number of samples in the ith stratum to the total number of samples, CV i : variability of the ith stratum, and E: sampling error percentage.
Since there was no information about the variation of the population, the coefficient of variation (CV) was accepted as 0.50, and the sampling error percentage (E) was accepted as 0.10 in the calculations.The calculated number of samples (n) was distributed proportionally to the strata (regions), and the number of samples for each region (n i ) was calculated.The samples distributed to the regions were further distributed to the sub-regions proportionally, taking into account the number of hospitals in the (n i,j ) sub-regions.
The potential number of days calculated by systematic sampling of the yearly meal menus of state university hospitals was 30 days.
Accordingly, the sampling interval was found to be 12.17 by dividing 365 by 30 and was accepted as approximately 12 days.Afterwards, a number between 1 and 12 was randomly selected, and a sampling calendar was created at 12-day intervals from the selected day of the year until the end of the year.Accordingly, at first, the number '4' was randomly selected.Hence, the sample pertaining to the 4th day of the year (January 4th) was accepted as the first sample, and then a total of 30 samples were determined for 30 days, including the samples pertaining to the 16th, 28th, 40th, 52nd, …, 352nd days.
The number of healthcare personnel (with different titles) working in the university hospitals included in the research is approximately 150 thousand, and the number of hospital beds is approximately 37 thousand.

| Standard meal menus of the state university hospitals
A total of 1260 single-day menus, including 30 menus from 42 hospitals, were analyzed.Nutrient contents and environmental footprint analyses of state university hospitals were conducted for the food groups included in the breakfast, lunch, and dinner of each state university hospital included in the study.Standard hospital diets and meals served to hospital staff were included in the analyses.
Therapeutic diets and meals served to pediatric patients were excluded from the study.Standard food recipes were used to evaluate the contents of the menus (both nutritional content and environmental footprint).In addition to 1-year meal menus, hospitals were also requested to provide the standard meal recipes they used during meal preparation.Standard recipes specify the serving size of each dish and the name and quantity of ingredients in the serving, and the study's calculations were made using the amounts included in these recipes.were reported as the average of regions (AOR).

| Evaluation of the water footprints of the standard and alternative state university hospital meal menus
The reference values reported in Mekonnen and Hoekstra's study (Mekonnen & Hoekstra, 2011), which contains weighted average WF data of many food products in different countries, including Turkey, were used to calculate the WF values of the menus investigated within the scope of this study.In WF calculations, only the WFs of the raw products were taken into account, while the WFs pertaining to the water used for cooking were not.The WF values for seafood and saltwater fish products were considered to be zero.The weighted average WF values of the food products included in the menus were multiplied by their respective amounts.All three types of WF, i.e., blue, green, and gray, were calculated for AOR, TDG, and MED.
WF values were calculated for each food in standard meal recipes as follows: Egg WF = water footprint of egg (m 3 /g −1 ) × average egg consumption (g).

| Evaluation of greenhouse gas emissions from the standard and alternative state university hospital meal menus
Since there is no national data on GHGE and carbon footprint values of foods produced in Turkey, the GHGE values given in kg/ product in Clune et al.'s study (Clune et al., 2017) were taken as references in calculating the GHGE values of regions AOR, TDG, and MED.
GHGE values were calculated for each food in standard meal recipes as follows: Egg GHGE = greenhouse gas emissions of egg (kg CO 2 -eq/g) * average egg consumption (g).

| Statistical analysis
The descriptive statistics obtained from the collected data were

| Ethical considerations
This study was conducted in accordance with the principles outlined in the Declaration of Helsinki.12.1 ± .

| Water footprints of the standard and alternative state university hospital meal menus
The green, blue, gray, and total WF values of regions, AOR, TDG, and MED are given in Figure 1.Accordingly, mean green, blue, gray, and total WF values of AOR were 115756.6 ± 15012.3L/ month, 12941.7 ± 12527.9L/month, 8581.9 ± 983.4 L/month, and 137,280 ± 18537.2L/month, respectively.The three regions with the highest total WF values were R6 (159255.0 ± 16253.7 L/month), R8 (150086.5 ± 4312.8L/month), and R2 (149260.9 ± 24872.3L/ month).In comparison, the mean total WF value of TDG was 103206.7 L/month and 24.8% less than the AOR, and the total WF value of MED was 85420.5 L/month and 37.8% less than the AOR (Figure 1).

| Greenhouse gas emissions from the standard and alternative state university hospital meal menus
The GHGE values of regions, AOR, TDG, and MED are shown in Figure 2. The GHGE values of AOR, TDG, and MED were 140.0 ± 18.4 kg CO2-equivalent/month, 95.5 kg CO2-eq/month, and 71.3 kg CO2-eq/month, respectively.Accordingly, TDG and MED had 31.7% and 49.0% less GHGE compared to AOR.Numerical data on the WF and GHGE values of hospital menus and alternative menus are given in Table S3.

| Distribution of water footprints and greenhouse gas emissions of the standard and alternative state university hospital meal menus by the food groups
The WF values of AOR, TDG, and MED by the food groups are shown in Figure 3a.Accordingly, it was determined that the three food groups with the highest total WF values in AOR were red meat (61.0%), milk and dairy products (15.2%), and poultry (6.4%), respectively.Similarly, the food groups with the highest total WF values in TDG and MED were red meat and milk and dairy products.However, the third food group with the highest WF in both TDG and MED was vegetables.
The GHGE values of AOR, TDG, and MED by the food groups are shown in Figure 3b.Accordingly, it was determined that the three food groups with the highest total GHGE values in AOR were red meat (50.3%), milk and dairy products (12.9%), and poultry (10.1%), respectively.The food groups with the highest total GHGE values in TDG were red meat (26.9%), milk and dairy products (24.5%), and cereals (15.8%), respectively.The food groups with the highest total GHGE values in MED were milk and dairy products (18.9%), cereals (16.4%), and oils (14.3%), respectively.
When food groups were compared in terms of quantity and WF per kilogram, it was seen that foods of animal origin had a higher WF value, considering the supply ratio of these foods in kilograms.
The inverse situation between the amount of food groups in kg and WF is shown in Figure 4a.The same reverse situation was observed between the amount of food groups in kg and GHGE (Figure 4b).

F I G U R E 1
The total (green, blue, and gray) water footprint (WF) of hospital menus and diet models (L/month).AOR, average of regions; MED, Mediterranean diet; R, region; TDG, Turkey Dietary Guidelines.This study was carried out to determine the environmental impacts of state university hospital's meal menus in Turkey.In addition, in line with the findings and recommendations of the relevant studies available in the literature (Aboussaleh et al., 2017;Berry et al., 2015;Burlingame & Dernini, 2011;Capone et al., 2013;Chaudhary & Krishna, 2019;Dernini et al., 2017;Dernini & Berry, 2015;Harris et al., 2020;Shahar et al., 2023;Springmann et al., 2018;Tompa et al., 2022;Vieux et al., 2018), the changes in the WF and GHGE values as a result of adjusting the standard meal menu of the state university hospitals according to TDG and Mediterranean nutritional models were determined.Consequently, the study's findings demonstrated that planning state university hospitals' meal menus based on TDG and Mediterranean nutritional models may reduce both WF and GHGE values.

| The impact of hospital menus on environmental sustainability
The healthcare sector, which aims to protect and improve the general population's health, poses a series of threats to the sustainability of the environment due to the intense amount of energy it uses (Dhillon & Kaur, 2015;Eckelman & Sherman, 2018;Faezipour & Ferreira, 2013, 2018;Karliner et al., 2019;World Health Organization, 2010).Food production is one of the leading causes of environmental degradation due to high GHGE, water scarcity, water and air pollution, and biodiversity loss (Mekonnen & Gerbens-Leenes, 2020;Milford & Kildal, 2019).Hospitals, one of the most important components of health systems, provide food service to employees, patients/families 24 h a day, 7 days a week, throughout the year (Eckelman & Sherman, 2018;GGHHA, 2015;Singh, 2019).
The World Health Organization has reported that healthcare facilities can reduce their environmental footprint by making changes to their food and beverage service practices, including limiting the amount of meat in hospital meals, producing the meals served to patients and staff in-house, purchasing local and organic products, etc., and helping prevent diseases by supporting access to food and nutrition (World Health Organization, 2010).Therefore, hospitals can model and promote health and sustainability through their food choices (NHS England, 2020).Details of the meal menus offered in hospitals in Turkey, such as the weekly frequency and amounts of meal groups, are specified in the Inpatient Treatment Institutions Operation Regulation (The Ministry of Health of Turkey, 1983).
However, the relevant regulation only covers the maximum frequency and quantity of food groups that can be served on meal menus.For example, the maximum daily dose for milk and yogurt is indicated as 250 g, and the maximum weekly frequency of milk and yogurt is indicated as 7 (Table S1).In this study, the differences in the distribution of environmental footprints (both WF and GHGE) of hospital hospitals by region indicate that the Inpatient Treatment Institutions Operation Regulation should also focus on the environmental impacts of hospital food services.Determining food menus within a framework that is both healthy and respectful to the environment can prevent such differences in the environmental F I G U R E 2 Greenhouse gas emission (GHGE) of hospital menus and diet models (g CO 2 -eq per month).AOR, average of regions; MED, Mediterranean diet; R, region; TDG, Turkey Dietary Guidelines.

| Dietary composition and environmental footprint
Dietary composition has a strong relationship with the environmental footprint.Diets high in energy, saturated fat, processed foods, added sugars, and red meat are thought to be associated with higher GHGE, land use, and water use compared to vegetable-based diets (Fanzo & Davis, 2019).It has been reported that reducing meat consumption and increasing the supply of fish and plant-based proteins such as beans, lentils, peas, and chickpeas may be an alternative to reducing the WF of menus offered without compromising nutritional quality (Nogueira et al., 2020).This study's findings indicated that AOR, TDG, and MED have comparable energy contents, yet AOR contains higher animal protein, lower vegetable protein, and higher saturated fat than TDG and MED; consequently, AOR has higher WF and GHGE compared to TDG and MED.
Animal origin foods are cited as the main cause of the environmental food-related footprint (Hoekstra, 2011;Röös et al., 2014).
Strasburg and Jahno (Strasburg & Jahno, 2017) demonstrated a positive association between the amount of meat and WF of food offered in university restaurants and recorded an average of 2 L of WF for each meal prepared, with the highest contribution coming from beef.The animal food group accounted for 77.9% of the WF, with beef and chicken being responsible for 62.2% of this value.
On the other hand, those of vegetable origin provided the highest amount in kilograms of food (65.5% of the total) with a WF of 21.2%.Hatjiathanassiadou et al. (Hatjiathanassiadou et al., 2019) found WF values per capita of 2752.4L for traditional lunch menus and 1113.9L for vegetarian menus.The difference in these values was due to the use of foods of animal origin, mainly beef.These results are similar to those found in the present study.In this study, it was determined that the share of red meat and poultry, the food group with the highest mean environmental footprint value, in the total WF value decreased by 32.6% and 53.1%, respectively, as a result of adjusting the standard meal menu of the state university hospitals according to TDG and MED nutritional models (not shown in the table).When food groups were compared in terms of quantity and WF per kilogram, it was seen that foods of animal origin had a higher WF and GHGE value, considering the supply ratio of these foods in kilograms (Figure 4).
There are many studies in the literature that show that reducing meat consumption is effective in reducing the environmental impact of the diet (Aleksandrowicz et al., 2016;Biesbroek et al., 2014;Geibel & Freund, 2023;Perignon et al., 2017).In this study, it was determined that the share of red meat in total GHGE decreased by 46.5% and 77.1% as a result of adjusting the standard meal menu of the state university hospitals according to TDG and MED (not shown in the Table ), and our findings are compatible with the literature.
The concept of diet sustainability refers to the nutritional adequacy, cultural acceptability, economic availability, and sustainable environmental impact of diets (Vieux et al., 2018).Studies investigating the environmental impact of alternative diets, e.g., vegetarian, vegan, or flexitarian, have reported that dietary scenarios containing fewer animal products have lower environmental impacts than the current diets (Baroni et al., 2007;Friel et al., 2009;Risku-Norja et al., 2008;Westhoek et al., 2014).However, meat and dairy products are high-quality sources of protein and micronutrients, and ensuring their adequate bioavailability is important for public health (Aleksandrowicz et al., 2016).Animal products are an important provider of some essential nutrients (such as Fe, vitamin B12, and n-3 fatty acids); therefore, restrictive and monotonous plant-based diets can lead to nutrient deficiencies that have detrimental effects on health (McEvoy et al., 2012).Additionally, hypothetical dietary scenarios do not represent actual food consumption in terms of food options and energy content and ignore the cultural acceptability component of diet sustainability (Vieux et al., 2018).The results of this study underline that a reduction in environmental footprint can be achieved without completely removing animal foods from the diet.In light of this information, we think that it would be more sustainable to focus on providing an overall reduction in the environmental footprint of meal menus by reducing the amounts of food groups that contribute to the WF and GHGE the most, rather than eliminating these food groups, particularly red meat, and adopting a food group-focused approach.

| The changes in the environmental footprint of the state university hospital meal menus when planned according to the Turkey dietary guidelines nutritional model
There is a significant global shift in the nutritional preferences of consumers, especially in developing countries, from fruits, vegetables, and grains to meat, dairy products, and processed foods (FAO, 2018).

| The changes in the environmental footprint of the state university hospital meal menus when planned according to the Mediterranean nutritional model
There has been increased interest in the Mediterranean diet as a sustainable dietary model in the international literature on transitioning to more sustainable food systems and diets (Aboussaleh et al., 2017;Berry et al., 2015;Blas et al., 2019;Burlingame & Dernini, 2011;Capone et al., 2013;Dernini et al., 2013Dernini et al., , 2017;;Dernini & Berry, 2015;Shahar et al., 2023).The Mediterranean diet is considered a model for the development of sustainable diets as it has low environmental impacts, is rich in biodiversity, has a high socio-cultural nutritional content, and has positive economic returns locally (Aboussaleh et al., 2017;Berry et al., 2015;Burlingame & Dernini, 2011;Dernini et al., 2013Dernini et al., , 2017;;Dernini & Berry, 2015).

| The strengths and limitations of the study
To the best of this study's authors' knowledge, in terms of sample size and number of menus evaluated, this study is the first in Turkey and one of the limited studies in the literature on the environmental footprint of hospital meal menus.A thorough review of the relevant literature revealed that the limited number of studies on the subject have addressed either the WF (Blas et al., 2016(Blas et al., , 2019;;Capone et al., 2013;Harris et al., 2020;Jalava et al., 2014) or GHGE (Drew et al., 2020;Gerber et al., 2013;Hyland et al., 2017;Vidal et al., 2015) of the hospital menus.In comparison, in this study, the environmental footprints of the hospital menus were investigated in terms of both WF and GHGE.We think that the findings of this study, which compares state university hospitals' standard meal menus and alternative menus based on TDG and Mediterranean nutritional models, will significantly contribute to the literature on sustainable nutrition.
Self-reported food consumption records can have a margin of error of up to approximately 22% due to under-reporting of both total food intake and specific food types (Ravelli & Schoeller, 2020;Vidal et al., 2015).Minimizing this error by using food purchasing data and actual portion sizes in calculating the environmental footprint of foods on menus is another strength of this study.On the other hand, the limitations of this study were that the environmental footprint of food waste could not be calculated and that only state university hospitals were included in the study.

| CON CLUS IONS
Considering the inseparable link between human and environmental health, it is imperative that hospitals, which are responsible for protecting and improving human health, also protect the environment.Hospitals serve millions of meals to patients and their families every year.Therefore, hospitals have a crucial role in both reducing the food-related environmental footprint of healthcare services and promoting healthy and sustainable eating habits.The authors of this study believe that in order to reduce the environmental footprint of hospital food services in Turkey, the serving quantities and frequency of serving of food groups offered in hospitals should be clearly determined by the Ministry of Health.In this study, only the meal menus of state university hospitals were considered.However, this study's results may guide further studies that will include all hospitals.Ensuring a food supply process and elaborating menu planning policies that can provide both healthy nutrition and the lowest possible environmental burden can contribute to transitioning to a healthy and sustainable diet across the population.

ACK N OWLED G M ENTS
The authors would like to thank the state university hospitals for contributing to our study by sharing data about hospital meal menus.
Data collection occurred from November 2021 to August 2022.During this time period, a one-year retrospective (2021) menu was requested from hospitals.As of 2020, 50 state university hospitals actively provide services in Turkey (The Ministry of Health of Turkey, 2021).Of these hospitals, eight hospitals that refused to share information were excluded from the study.In the end, the yearly meal menus of 42 state university hospitals were evaluated within the scope of the study.The stratified sampling method was used to ensure homogeneity in terms of geographical regions.Accordingly, each of the 12 service regions defined in the Health Statistics Yearbook of the Ministry of Health of the Republic of Turkey (Mediterranean: R1; Western Anatolia: R2; Western Black Sea: R3; Western Marmara: R4; Eastern Black Sea: R5; Eastern Marmara: R6; Aegean Region: R7; Southeastern Anatolia: R8; Istanbul Region: R9; Northeastern Anatolia: R10; Middle Eastern Anatolia: R11; Central Anatolia: R12) (The Ministry of Health of Turkey, 2021) was accepted as a stratum, and the calculated number of samples was distributed to these strata by the "proportional distribution" method.
footprints of different hospitals affiliated with the same institution.Considering that the WF and GHGE values of menus are parallel to each other, it seems possible that correct menu planning principles can reduce both environmental footprints.The findings of our study also demonstrated that existing hospital meal menus can be changed to healthier (lower saturated fat and cholesterol, higher dietary fiber) F I G U R E 3 Distribution percentages of water footprint (WF) (a) and greenhouse gas emission (GHGE) (b) of hospital menus and diet models according to food groups.AOR, average of regions; MED, Mediterranean diet; R, region; TDG, Turkey Dietary Guidelines.